This invention relates to apparatus for use in medical proceedures, and more particularly to irrigation apparatus in which the direction of fluid flow may be rapidly reversed and particulate matter in the circulating fluid may be rapidly removed, thereby facilitating lavage.
Medical irrigation devices are well-known, and are particularly used in urology for lavage in a variety of procedures, such as the treatment of chronic infections, the cleansing of the inspection field prior to cystoscopy, and the post-operative treatment of the urinary bladder.
A common prior art device widely utilized for irrigation of the urinary bladder is the so-called Ellik evacuator. This device comprises a unitary body, typically of glass, forming a pair of hollow chambers the interiors of which directly communicate with one another through a short restricted passageway. One of the chambers is further provided with a pair of conduits communicating with its interior, one of such conduits being provided with means for connecting it with a cannula, such as a resectoscope or similar device, and the other conduit being adapted to be connected to a bulb-type syringe. In use, the syringe and both chambers of the Ellik evacuator are filled with a suitable sterile fluid, and the resectoscope or like catheter is introducted into the urinary bladder or other body cavity to be irrigated. Compression of the syringe then introduces the fluid into the body cavity, and expansion of the syringe withdraws it. If the evacuator is held such that the chamber having the conduits communicating with the syringe and the resectoscope is uppermost, then particulate matter carried by the fluid stream into the evacuator during the expansion of the syringe, may settle by gravity into the lower chamber, provided of course that the density of the particles is greater than that of the fluid. Once the particulate matter has settled into the lower chamber, the restricted passageway between the two chambers acts to minimize this material from being agitated by, and drawn again into, the flow stream passing through the upper chamber, between syringe and catheter.
A disadvantage of the Ellik evacuator is the slow rate of precipitation of the particulate matter, much of which has a density not unlike that of water. As a consequence, if the syringe is rapidly and cyclically compressed and expanded in order to produce vigorous agitation during lavage, a large percentage of the particulate matter evacuated during the expansion of the syringe will remain in suspension in the upper chamber and be re-introduced into the body cavity during the next compression cycle of the syringe, or alternatively be drawn into the syringe and trapped therein. Even if vigorous agitation is not desired, the use of gravity to effect separation of the debris from the fluid results in a time-consuming lavage procedure. A further disadvantage of the Ellik evacuator is that, in order to subject to laboratory examination the particulate matter collected in the evacuator, it is necessary to remove the material collected in the lower chamber as well as in the upper chamber and syringe, a time-consuming procedure which may not be performed with confidence that there will be no loss.
A variety of evacuators have been devised to overcome these disadvantages. A common approach is to provide the evacuator with a fluid-transmissive manifold having a pair of separate paths, one path for the fluid injected into the body cavity and one for the fluid removed. The debris-ladened fluid drained from the body cavity may either by separately collected, with new sterile fluid being supplied for lavage, as in U.S. Pat. No. 3,233,609, or it may be filtered and recycled, as in U.S. Pat. Nos. 1,925,230, and 3,892,226, among others.
It is clear that the first of these types of apparatus requires large reservoirs for the sterile fluid and the effluent, particularly if a substantial quantity of fluid is to be circulated through the body cavity being cleansed. This in turn requires the reservoirs be connected to the manifold by lengths of sterile flexible tubing if the surgeon is to easily manipulate the apparatus. Fluid circulation in such evacuators is generally gravity powered, and is controlled by the coordinated operation of a pair of manually operated valves, one between the manifold and the sterile fluid reservoir and the other between the manifold and the collection receptacle, although a syringe may be added (as indeed it is in U.S. Pat. No. 3,233,309) to provide alternate pressure and suction if desired. A disadvantage of this type of evacuator is in its complexity. Not only does it consist of a number of parts which must be assembled in sterile condition for use, but its very use is somewhat cumbersome, requiring as it does the sumultaneous manipulation of not only a catheter and a syringe, but also of several valves, the whole connected together and to various reservoirs by lengths of flexible tubing.
The second type of apparatus, by filtering and recirculating the initially sterile fluid, avoids a number of these problems. Since the fluid is recirculated, only small reservoirs are needed, and the entire unit may be hand held, as is the Ellik evacuator. As the fluid is circulated by the alternate compression and expansion of a syringe, flow control may be accomplished by a pair of automatically operated check valves arranged to provide unidirectional flow of fluid through the filter. Aside from the loss in performance that slow acting and/or jammed valves can produce, such apparatus is relatively complex, requiring the assembly of a number of parts, and is consequently difficult to clean during use and to sterilize if used more than once. Further, such evacuators are not as inexpensive as the Ellik evacuator if used only once.